git.gag.com Git - fw/openocd/blob - src/jtag/presto.c

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Pavel Chromy                                    *
   3  *   chromy@asix.cz                                                        *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #if IS_CYGWIN == 1
  25 #include "windows.h"
  26 #endif
  27
  28 #include "replacements.h"
  29
  30 /* project specific includes */
  31 #include "log.h"
  32 #include "types.h"
  33 #include "jtag.h"
  34 #include "configuration.h"
  35 #include "time_support.h"
  36 #include "bitq.h"
  37
  38 /* system includes */
  39 #include <string.h>
  40 #include <stdlib.h>
  41 #include <unistd.h>
  42
  43 /* PRESTO access library includes */
  44 #if BUILD_PRESTO_FTD2XX == 1
  45 #include <ftd2xx.h>
  46 #elif BUILD_PRESTO_LIBFTDI == 1
  47 #include <ftdi.h>
  48 #else
  49 #error "BUG: either FTD2XX and LIBFTDI has to be used"
  50 #endif
  51
  52 static int presto_jtag_speed(int speed);
  53 static int presto_jtag_khz(int khz, int *jtag_speed);
  54 static int presto_jtag_speed_div(int speed, int *khz);
  55 static int presto_jtag_register_commands(struct command_context_s *cmd_ctx);
  56 static int presto_jtag_init(void);
  57 static int presto_jtag_quit(void);
  58
  59 jtag_interface_t presto_interface =
  60 {
  61         .name = "presto",
  62         .execute_queue = bitq_execute_queue,
  63         .speed = presto_jtag_speed,
  64         .khz = presto_jtag_khz,
  65         .speed_div = presto_jtag_speed_div,
  66         .register_commands = presto_jtag_register_commands,
  67         .init = presto_jtag_init,
  68         .quit = presto_jtag_quit,
  69 };
  70
  71 static int presto_bitq_out(int tms, int tdi, int tdo_req);
  72 static int presto_bitq_flush(void);
  73 static int presto_bitq_sleep(unsigned long us);
  74 static int presto_bitq_reset(int trst, int srst);
  75 static int presto_bitq_in_rdy(void);
  76 static int presto_bitq_in(void);
  77
  78 static bitq_interface_t presto_bitq =
  79 {
  80         .out = presto_bitq_out,
  81         .flush = presto_bitq_flush,
  82         .sleep = presto_bitq_sleep,
  83         .reset = presto_bitq_reset,
  84         .in_rdy = presto_bitq_in_rdy,
  85         .in = presto_bitq_in,
  86 };
  87
  88 /* -------------------------------------------------------------------------- */
  89
  90 #define FT_DEVICE_NAME_LEN 64
  91 #define FT_DEVICE_SERNUM_LEN 64
  92
  93 #define PRESTO_VID_PID 0x0403f1a0
  94 #define PRESTO_VID (0x0403)
  95 #define PRESTO_PID (0xf1a0)
  96
  97 #define BUFFER_SIZE (64*62)
  98
  99 typedef struct presto_s
 100 {
 101 #if BUILD_PRESTO_FTD2XX == 1
 102         FT_HANDLE handle;
 103         FT_STATUS status;
 104 #elif BUILD_PRESTO_LIBFTDI == 1
 105         struct ftdi_context ftdic;
 106         int retval;
 107 #endif
 108
 109         char serial[FT_DEVICE_SERNUM_LEN];
 110
 111         u8 buff_out[BUFFER_SIZE];
 112         int buff_out_pos;
 113
 114         u8 buff_in[BUFFER_SIZE];
 115         int buff_in_exp; /* expected in buffer length */
 116         int buff_in_len; /* length of data received */
 117         int buff_in_pos;
 118
 119         unsigned long total_out;
 120         unsigned long total_in;
 121
 122         int jtag_tms; /* last tms state */
 123         int jtag_tck; /* last tck state */
 124         int jtag_rst; /* last trst state */
 125
 126         int jtag_tdi_data;
 127         int jtag_tdi_count;
 128
 129         int jtag_speed;
 130
 131 } presto_t;
 132
 133 static presto_t presto_state;
 134 static presto_t *presto = &presto_state;
 135
 136 static u8 presto_init_seq[] =
 137 {
 138         0x80, 0xA0, 0xA8, 0xB0, 0xC0, 0xE0
 139 };
 140
 141 static int presto_write(u8 *buf, u32 size)
 142 {
 143 #if BUILD_PRESTO_FTD2XX == 1
 144         DWORD ftbytes;
 145         if ((presto->status = FT_Write(presto->handle, buf, size, &ftbytes)) != FT_OK)
 146         {
 147                 LOG_ERROR("FT_Write returned: %lu", presto->status);
 148                 return ERROR_JTAG_DEVICE_ERROR;
 149         }
 150
 151 #elif BUILD_PRESTO_LIBFTDI == 1
 152         u32 ftbytes;
 153         if ((presto->retval = ftdi_write_data(&presto->ftdic, buf, size)) < 0)
 154         {
 155                 LOG_ERROR("ftdi_write_data: %s", ftdi_get_error_string(&presto->ftdic));
 156                 return ERROR_JTAG_DEVICE_ERROR;
 157         }
 158         ftbytes = presto->retval;
 159 #endif
 160
 161         if (ftbytes != size)
 162         {
 163                 LOG_ERROR("couldn't write the requested number of bytes to PRESTO (%u < %u)", (u32)ftbytes, size);
 164                 return ERROR_JTAG_DEVICE_ERROR;
 165         }
 166
 167         return ERROR_OK;
 168 }
 169
 170 static int presto_read(u8* buf, u32 size)
 171 {
 172 #if BUILD_PRESTO_FTD2XX == 1
 173         DWORD ftbytes;
 174         if ((presto->status = FT_Read(presto->handle, buf, size, &ftbytes)) != FT_OK)
 175         {
 176                 LOG_ERROR("FT_Read returned: %lu", presto->status);
 177                 return ERROR_JTAG_DEVICE_ERROR;
 178         }
 179
 180 #elif BUILD_PRESTO_LIBFTDI == 1
 181         u32 ftbytes = 0;
 182
 183         struct timeval timeout, now;
 184         gettimeofday(&timeout, NULL);
 185         timeval_add_time(&timeout, 1, 0); /* one second timeout */
 186
 187         while (ftbytes < size)
 188         {
 189                 if ((presto->retval = ftdi_read_data(&presto->ftdic, buf + ftbytes, size - ftbytes)) < 0)
 190                 {
 191                         LOG_ERROR("ftdi_read_data: %s", ftdi_get_error_string(&presto->ftdic));
 192                         return ERROR_JTAG_DEVICE_ERROR;
 193                 }
 194                 ftbytes += presto->retval;
 195
 196                 gettimeofday(&now, NULL);
 197                 if ((now.tv_sec > timeout.tv_sec) || ((now.tv_sec == timeout.tv_sec) && (now.tv_usec > timeout.tv_usec)))
 198                         break;
 199         }
 200 #endif
 201
 202         if (ftbytes != size)
 203         {
 204                 /* this is just a warning, there might have been timeout when detecting PRESTO, which is not fatal */
 205                 LOG_WARNING("couldn't read the requested number of bytes from PRESTO (%u < %u)", (u32)ftbytes, size);
 206                 return ERROR_JTAG_DEVICE_ERROR;
 207         }
 208
 209         return ERROR_OK;
 210 }
 211
 212 #if BUILD_PRESTO_FTD2XX == 1
 213 static int presto_open_ftd2xx(char *req_serial)
 214 {
 215         u32 i;
 216         DWORD numdevs;
 217         DWORD vidpid;
 218         char devname[FT_DEVICE_NAME_LEN];
 219         FT_DEVICE device;
 220
 221         BYTE presto_data;
 222         DWORD ftbytes;
 223
 224         presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 225
 226 #if IS_WIN32 == 0
 227         /* Add non-standard Vid/Pid to the linux driver */
 228         if ((presto->status = FT_SetVIDPID(PRESTO_VID, PRESTO_PID)) != FT_OK)
 229         {
 230                 LOG_ERROR("couldn't add PRESTO VID/PID");
 231                 exit(-1);
 232         }
 233 #endif
 234
 235         if ((presto->status = FT_ListDevices(&numdevs, NULL, FT_LIST_NUMBER_ONLY)) != FT_OK)
 236         {
 237                 LOG_ERROR("FT_ListDevices failed: %i", (int)presto->status);
 238                 return ERROR_JTAG_DEVICE_ERROR;
 239         }
 240
 241         LOG_DEBUG("FTDI devices available: %lu", numdevs);
 242         for (i = 0; i < numdevs; i++)
 243         {
 244                 if ((presto->status = FT_Open(i, &(presto->handle))) != FT_OK)
 245                 {
 246                         /* this is not fatal, the device may be legitimately open by other process, hence debug message only */
 247                         LOG_DEBUG("FT_Open failed: %i", (int)presto->status);
 248                         continue;
 249                 }
 250                 LOG_DEBUG("FTDI device %i open", i);
 251
 252                 if ((presto->status = FT_GetDeviceInfo(presto->handle, &device, &vidpid,
 253                                 presto->serial, devname, NULL)) == FT_OK)
 254                 {
 255                         if (vidpid == PRESTO_VID_PID
 256                                         && (req_serial == NULL || !strcmp(presto->serial, req_serial)))
 257                                 break;
 258                 }
 259                 else
 260                         LOG_DEBUG("FT_GetDeviceInfo failed: %lu", presto->status);
 261
 262                 LOG_DEBUG("FTDI device %i does not match, closing", i);
 263                 FT_Close(presto->handle);
 264                 presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 265         }
 266
 267         if (presto->handle == (FT_HANDLE)INVALID_HANDLE_VALUE)
 268                 return ERROR_JTAG_DEVICE_ERROR; /* presto not open, return */
 269
 270         if ((presto->status = FT_SetLatencyTimer(presto->handle, 1)) != FT_OK)
 271                 return ERROR_JTAG_DEVICE_ERROR;
 272
 273
 274         if ((presto->status = FT_SetTimeouts(presto->handle, 100, 0)) != FT_OK)
 275                 return ERROR_JTAG_DEVICE_ERROR;
 276
 277         if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 278                 return ERROR_JTAG_DEVICE_ERROR;
 279
 280         presto_data = 0xD0;
 281         if ((presto->status = FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 282                 return ERROR_JTAG_DEVICE_ERROR;
 283
 284         /* delay between first write/read turnaround (after purge?) necessary under Linux for unknown reason,
 285            probably a bug in library threading */
 286         usleep(100000);
 287         if ((presto->status = FT_Read(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 288                 return ERROR_JTAG_DEVICE_ERROR;
 289
 290         if (ftbytes!=1)
 291         {
 292                 LOG_DEBUG("PRESTO reset");
 293
 294                 if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 295                         return ERROR_JTAG_DEVICE_ERROR;
 296                 if ((presto->status = FT_SetBitMode(presto->handle, 0x80, 1)) != FT_OK)
 297                         return ERROR_JTAG_DEVICE_ERROR;
 298                 if ((presto->status = FT_SetBaudRate(presto->handle, 9600)) != FT_OK)
 299                         return ERROR_JTAG_DEVICE_ERROR;
 300
 301                 presto_data = 0;
 302                 for (i = 0; i < 4 * 62; i++)
 303                         if ((presto->status=FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 304                                 return ERROR_JTAG_DEVICE_ERROR;
 305
 306                 usleep(100000);
 307
 308                 if ((presto->status = FT_SetBitMode(presto->handle, 0x00, 0)) != FT_OK)
 309                         return ERROR_JTAG_DEVICE_ERROR;
 310
 311                 if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 312                         return ERROR_JTAG_DEVICE_ERROR;
 313
 314                 presto_data = 0xD0;
 315                 if ((presto->status = FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 316                         return ERROR_JTAG_DEVICE_ERROR;
 317
 318                 /* delay between first write/read turnaround (after purge?) necessary under Linux for unknown reason,
 319                    probably a bug in library threading */
 320                 usleep(100000);
 321                 if ((presto->status = FT_Read(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 322                         return ERROR_JTAG_DEVICE_ERROR;
 323
 324                 if (ftbytes!=1)
 325                 {
 326                         LOG_DEBUG("PRESTO not responding");
 327                         return ERROR_JTAG_DEVICE_ERROR;
 328                 }
 329         }
 330
 331         if ((presto->status = FT_SetTimeouts(presto->handle, 0, 0)) != FT_OK)
 332                 return ERROR_JTAG_DEVICE_ERROR;
 333
 334
 335         presto->status = FT_Write(presto->handle, &presto_init_seq, sizeof(presto_init_seq), &ftbytes);
 336         if (presto->status != FT_OK || ftbytes != sizeof(presto_init_seq))
 337                 return ERROR_JTAG_DEVICE_ERROR;
 338
 339         return ERROR_OK;
 340 }
 341
 342 #elif BUILD_PRESTO_LIBFTDI == 1
 343 static int presto_open_libftdi(char *req_serial)
 344 {
 345         u8 presto_data;
 346
 347         LOG_DEBUG("searching for PRESTO using libftdi");
 348
 349         /* initialize FTDI context structure */
 350         if (ftdi_init(&presto->ftdic) < 0)
 351         {
 352                 LOG_ERROR("unable to init libftdi: %s", presto->ftdic.error_str);
 353                 return ERROR_JTAG_DEVICE_ERROR;
 354         }
 355
 356         /* context, vendor id, product id */
 357         if (ftdi_usb_open_desc(&presto->ftdic, PRESTO_VID, PRESTO_PID, NULL, req_serial) < 0)
 358         {
 359                 LOG_ERROR("unable to open PRESTO: %s", presto->ftdic.error_str);
 360                 return ERROR_JTAG_DEVICE_ERROR;
 361         }
 362
 363         if (ftdi_usb_reset(&presto->ftdic) < 0)
 364         {
 365                 LOG_ERROR("unable to reset PRESTO device");
 366                 return ERROR_JTAG_DEVICE_ERROR;
 367         }
 368
 369         if (ftdi_set_latency_timer(&presto->ftdic, 1) < 0)
 370         {
 371                 LOG_ERROR("unable to set latency timer");
 372                 return ERROR_JTAG_DEVICE_ERROR;
 373         }
 374
 375         if (ftdi_usb_purge_buffers(&presto->ftdic) < 0)
 376         {
 377                 LOG_ERROR("unable to purge PRESTO buffers");
 378                 return ERROR_JTAG_DEVICE_ERROR;
 379         }
 380
 381         presto_data = 0xD0;
 382         if (presto_write(&presto_data, 1) != ERROR_OK)
 383         {
 384                 LOG_ERROR("error writing to PRESTO");
 385                 return ERROR_JTAG_DEVICE_ERROR;
 386         }
 387
 388         if (presto_read(&presto_data, 1) != ERROR_OK)
 389         {
 390                 LOG_DEBUG("no response from PRESTO, retrying");
 391
 392                 if (ftdi_usb_purge_buffers(&presto->ftdic) < 0)
 393                         return ERROR_JTAG_DEVICE_ERROR;
 394
 395                 presto_data = 0xD0;
 396                 if (presto_write(&presto_data, 1) != ERROR_OK)
 397                         return ERROR_JTAG_DEVICE_ERROR;
 398
 399                 if (presto_read(&presto_data, 1) != ERROR_OK)
 400                 {
 401                         LOG_ERROR("no response from PRESTO, giving up");
 402                         return ERROR_JTAG_DEVICE_ERROR;
 403                 }
 404         }
 405
 406         if (presto_write(presto_init_seq, sizeof(presto_init_seq)) != ERROR_OK)
 407         {
 408                 LOG_ERROR("error writing PRESTO init sequence");
 409                 return ERROR_JTAG_DEVICE_ERROR;
 410         }
 411
 412         return ERROR_OK;
 413 }
 414 #endif /* BUILD_PRESTO_LIBFTDI == 1 */
 415
 416 static int presto_open(char *req_serial)
 417 {
 418         presto->buff_out_pos=0;
 419         presto->buff_in_pos=0;
 420         presto->buff_in_len=0;
 421         presto->buff_in_exp=0;
 422
 423         presto->total_out=0;
 424         presto->total_in=0;
 425
 426         presto->jtag_tms=0;
 427         presto->jtag_tck=0;
 428         presto->jtag_rst=0;
 429         presto->jtag_tdi_data=0;
 430         presto->jtag_tdi_count=0;
 431
 432         presto->jtag_speed=0;
 433
 434 #if BUILD_PRESTO_FTD2XX == 1
 435         return presto_open_ftd2xx(req_serial);
 436 #elif BUILD_PRESTO_LIBFTDI == 1
 437         return presto_open_libftdi(req_serial);
 438 #endif
 439 }
 440
 441 static int presto_close(void)
 442 {
 443
 444         int result = ERROR_OK;
 445
 446 #if BUILD_PRESTO_FTD2XX == 1
 447         unsigned long ftbytes;
 448
 449         if (presto->handle == (FT_HANDLE)INVALID_HANDLE_VALUE)
 450                 return result;
 451
 452         presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX);
 453         if (presto->status != FT_OK)
 454                 result = ERROR_JTAG_DEVICE_ERROR;
 455
 456         presto->status = FT_Write(presto->handle, &presto_init_seq, sizeof(presto_init_seq), &ftbytes);
 457         if (presto->status != FT_OK || ftbytes != sizeof(presto_init_seq))
 458                 result = ERROR_JTAG_DEVICE_ERROR;
 459
 460         if ((presto->status = FT_SetLatencyTimer(presto->handle, 16)) != FT_OK)
 461                 result = ERROR_JTAG_DEVICE_ERROR;
 462
 463         if ((presto->status = FT_Close(presto->handle)) != FT_OK)
 464                 result = ERROR_JTAG_DEVICE_ERROR;
 465         else
 466                 presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 467
 468 #elif BUILD_PRESTO_LIBFTDI == 1
 469
 470         if ((presto->retval = ftdi_write_data(&presto->ftdic, presto_init_seq, sizeof(presto_init_seq))) != sizeof(presto_init_seq))
 471                 result = ERROR_JTAG_DEVICE_ERROR;
 472
 473         if ((presto->retval = ftdi_set_latency_timer(&presto->ftdic, 16)) < 0)
 474                 result = ERROR_JTAG_DEVICE_ERROR;
 475
 476         if ((presto->retval = ftdi_usb_close(&presto->ftdic)) < 0)
 477                 result = ERROR_JTAG_DEVICE_ERROR;
 478         else
 479                 ftdi_deinit(&presto->ftdic);
 480 #endif
 481
 482         return result;
 483 }
 484
 485 static int presto_flush(void)
 486 {
 487         if (presto->buff_out_pos == 0)
 488                 return ERROR_OK;
 489
 490 #if BUILD_PRESTO_FTD2XX == 1
 491         if (presto->status != FT_OK)
 492 #elif BUILD_PRESTO_LIBFTDI == 1
 493         if (presto->retval < 0)
 494 #endif
 495         {
 496                 LOG_DEBUG("error in previous communication, canceling I/O operation");
 497                 return ERROR_JTAG_DEVICE_ERROR;
 498         }
 499
 500         if (presto_write(presto->buff_out, presto->buff_out_pos) != ERROR_OK)
 501         {
 502                 presto->buff_out_pos = 0;
 503                 return ERROR_JTAG_DEVICE_ERROR;
 504         }
 505
 506         presto->total_out += presto->buff_out_pos;
 507         presto->buff_out_pos = 0;
 508
 509         if (presto->buff_in_exp == 0)
 510                 return ERROR_OK;
 511
 512         presto->buff_in_pos = 0;
 513         presto->buff_in_len = 0;
 514
 515         if (presto_read(presto->buff_in, presto->buff_in_exp) != ERROR_OK)
 516         {
 517                 presto->buff_in_exp = 0;
 518                 return ERROR_JTAG_DEVICE_ERROR;
 519         }
 520
 521         presto->total_in += presto->buff_in_exp;
 522         presto->buff_in_len = presto->buff_in_exp;
 523         presto->buff_in_exp = 0;
 524
 525         return ERROR_OK;
 526 }
 527
 528 static int presto_sendbyte(int data)
 529 {
 530         if (data == EOF) return presto_flush();
 531
 532         if (presto->buff_out_pos < BUFFER_SIZE)
 533         {
 534                 presto->buff_out[presto->buff_out_pos++] = (u8)data;
 535                 if (((data & 0xC0) == 0x40) || ((data & 0xD0)== 0xD0))
 536                         presto->buff_in_exp++;
 537         }
 538         else
 539                 return ERROR_JTAG_DEVICE_ERROR;
 540
 541 #if BUILD_PRESTO_FTD2XX == 1
 542         if (presto->buff_out_pos >= BUFFER_SIZE)
 543 #elif BUILD_PRESTO_LIBFTDI == 1
 544         /* libftdi does not do background read, be sure that USB IN buffer does not overflow (128 bytes only!) */
 545         if (presto->buff_out_pos >= BUFFER_SIZE || presto->buff_in_exp==128)
 546 #endif
 547                 return presto_flush();
 548
 549         return ERROR_OK;
 550 }
 551
 552 #if 0
 553 static int presto_getbyte(void)
 554 {
 555         if (presto->buff_in_pos < presto->buff_in_len)
 556                 return presto->buff_in[presto->buff_in_pos++];
 557
 558         if (presto->buff_in_exp == 0)
 559                 return -1;
 560
 561         if (presto_flush() != ERROR_OK)
 562                 return -1;
 563
 564         if (presto->buff_in_pos<presto->buff_in_len)
 565                 return presto->buff_in[presto->buff_in_pos++];
 566
 567         return -1;
 568 }
 569 #endif
 570
 571 /* -------------------------------------------------------------------------- */
 572
 573 static int presto_tdi_flush(void)
 574 {
 575         if (presto->jtag_tdi_count == 0)
 576                 return 0;
 577
 578         if (presto->jtag_tck == 0)
 579         {
 580                 LOG_ERROR("BUG: unexpected TAP condition, TCK low");
 581                 return -1;
 582         }
 583
 584         presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
 585         presto_sendbyte(presto->jtag_tdi_data);
 586         presto->jtag_tdi_count = 0;
 587         presto->jtag_tdi_data = 0;
 588
 589         return 0;
 590 }
 591
 592 static int presto_tck_idle(void)
 593 {
 594         if (presto->jtag_tck == 1)
 595         {
 596                 presto_sendbyte(0xCA);
 597                 presto->jtag_tck = 0;
 598         }
 599
 600         return 0;
 601 }
 602
 603 /* -------------------------------------------------------------------------- */
 604
 605 static int presto_bitq_out(int tms, int tdi, int tdo_req)
 606 {
 607         int i;
 608         unsigned char cmd;
 609
 610         if (presto->jtag_tck == 0)
 611         {
 612                 presto_sendbyte(0xA4); /* LED idicator - JTAG active */
 613         }
 614         else if (presto->jtag_speed == 0 && !tdo_req && tms == presto->jtag_tms)
 615         {
 616                 presto->jtag_tdi_data |= (tdi != 0) << presto->jtag_tdi_count;
 617
 618                 if (++presto->jtag_tdi_count == 4)
 619                         presto_tdi_flush();
 620
 621                 return 0;
 622         }
 623
 624         presto_tdi_flush();
 625
 626         cmd = tdi ? 0xCB : 0xCA;
 627         presto_sendbyte(cmd);
 628
 629         if (tms != presto->jtag_tms)
 630         {
 631                 presto_sendbyte((tms ? 0xEC : 0xE8) | (presto->jtag_rst ? 0x02 : 0));
 632                 presto->jtag_tms = tms;
 633         }
 634
 635         /* delay with TCK low */
 636         for (i=presto->jtag_speed; i>1; i--)
 637                 presto_sendbyte(cmd);
 638
 639         cmd |= 0x04;
 640         presto_sendbyte(cmd | (tdo_req ? 0x10 : 0));
 641
 642         /* delay with TCK high */
 643         for (i=presto->jtag_speed; i>1; i--)
 644                 presto_sendbyte(cmd);
 645
 646         presto->jtag_tck = 1;
 647
 648         return 0;
 649 }
 650
 651 static int presto_bitq_flush(void)
 652 {
 653         presto_tdi_flush();
 654         presto_tck_idle();
 655
 656         presto_sendbyte(0xA0); /* LED idicator - JTAG idle */
 657
 658         return presto_flush();
 659 }
 660
 661 static int presto_bitq_in_rdy(void)
 662 {
 663         if (presto->buff_in_pos>=presto->buff_in_len)
 664                 return 0;
 665         return presto->buff_in_len-presto->buff_in_pos;
 666 }
 667
 668 static int presto_bitq_in(void)
 669 {
 670         if (presto->buff_in_pos>=presto->buff_in_len)
 671                 return -1;
 672         if (presto->buff_in[presto->buff_in_pos++]&0x08) return 1;
 673         return 0;
 674 }
 675
 676 static int presto_bitq_sleep(unsigned long us)
 677 {
 678         long waits;
 679
 680         presto_tdi_flush();
 681         presto_tck_idle();
 682
 683         if (us > 100000)
 684         {
 685                 presto_bitq_flush();
 686                 jtag_sleep(us);
 687                 return 0;
 688         }
 689
 690         waits = us / 170 + 2;
 691         while (waits--)
 692                 presto_sendbyte(0x80);
 693
 694         return 0;
 695 }
 696
 697 static int presto_bitq_reset(int trst, int srst)
 698 {
 699         presto_tdi_flush();
 700         presto_tck_idle();
 701
 702         /* add a delay after possible TCK transition */
 703         presto_sendbyte(0x80);
 704         presto_sendbyte(0x80);
 705
 706         presto->jtag_rst = trst || srst;
 707         presto_sendbyte((presto->jtag_rst ? 0xEA : 0xE8) | (presto->jtag_tms ? 0x04 : 0));
 708
 709         return 0;
 710 }
 711
 712 /* -------------------------------------------------------------------------- */
 713
 714 static int presto_jtag_khz(int khz, int *jtag_speed)
 715 {
 716         if (khz < 0)
 717         {
 718                 *jtag_speed=0;
 719                 return ERROR_INVALID_ARGUMENTS;
 720         }
 721
 722         if (khz >= 3000) *jtag_speed = 0;
 723         else *jtag_speed = (1000+khz-1)/khz;
 724
 725         return 0;
 726 }
 727
 728 static int presto_jtag_speed_div(int speed, int *khz)
 729 {
 730         if ((speed < 0) || (speed > 1000))
 731         {
 732                 *khz=0;
 733                 return ERROR_INVALID_ARGUMENTS;
 734         }
 735
 736         if (speed == 0) *khz = 3000;
 737         else *khz = 1000/speed;
 738
 739         return 0;
 740 }
 741
 742 static int presto_jtag_speed(int speed)
 743 {
 744         int khz;
 745
 746         if (presto_jtag_speed_div(speed, &khz))
 747         {
 748                 return ERROR_INVALID_ARGUMENTS;
 749         }
 750
 751         presto->jtag_speed = speed;
 752
 753         if (khz%1000 == 0)
 754                 LOG_INFO("setting speed to %d, max. TCK freq. is %d MHz", speed, khz/1000);
 755         else
 756                 LOG_INFO("setting speed to %d, max. TCK freq. is %d kHz", speed, khz);
 757
 758         return 0;
 759 }
 760
 761 static char *presto_serial;
 762
 763 static int presto_handle_serial_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 764 {
 765         if (argc == 1)
 766         {
 767                 if (presto_serial)
 768                         free(presto_serial);
 769                 presto_serial = strdup(args[0]);
 770         }
 771         else
 772         {
 773                 LOG_ERROR("expected exactly one argument to presto_serial <serial-number>");
 774         }
 775
 776         return ERROR_OK;
 777 }
 778
 779 static int presto_jtag_register_commands(struct command_context_s *cmd_ctx)
 780 {
 781         register_command(cmd_ctx, NULL, "presto_serial", presto_handle_serial_command,
 782                 COMMAND_CONFIG, NULL);
 783         return ERROR_OK;
 784 }
 785
 786 static int presto_jtag_init(void)
 787 {
 788         if (presto_open(presto_serial) != ERROR_OK)
 789         {
 790                 presto_close();
 791                 if (presto_serial != NULL)
 792                         LOG_ERROR("Cannot open PRESTO, serial number '%s'", presto_serial);
 793                 else
 794                         LOG_ERROR("Cannot open PRESTO");
 795                 return ERROR_JTAG_INIT_FAILED;
 796         }
 797         LOG_INFO("PRESTO open, serial number '%s'", presto->serial);
 798
 799         /* use JTAG speed setting from configuration file */
 800         presto_jtag_speed(jtag_speed);
 801
 802         bitq_interface = &presto_bitq;
 803         return ERROR_OK;
 804 }
 805
 806 static int presto_jtag_quit(void)
 807 {
 808         bitq_cleanup();
 809         presto_close();
 810         LOG_INFO("PRESTO closed");
 811
 812         if (presto_serial)
 813         {
 814                 free(presto_serial);
 815                 presto_serial = NULL;
 816         }
 817
 818         return ERROR_OK;
 819 }